This magnificent new superzoom encompasses all popular focal lengths from the 50mm ''normal'' to 500mm ultra-telephoto; a 10:1 zoom ratio, providing tremendous versatility. The use of an apochromatic design and four elements composed of SLD (Special Low Dispersion) glass, plus a seven group zoom system and multi-coated optics, enable this wide-ranging zoom lens to provide a high level of performance, as well as versatility. It also employs a rear focus system to insure quick, convenient manual focus and a non-rotating front barrel.

The 50-500mm f4-6.3 EX APO RF HSM is coupled with Sigma's HSM (Hyper Sonic Motor), to provide quiet, responsive autofocus function, plus ''full time'' manual focus. This lens also features a Zoom Lock mechanism to help eliminate ''zoom creep'' when the lens is tilted up or down.

Sigma uses magnesium in the tripod mount to help reduce the weight of this lens, while maintaining the strength and rigidity necessary to support it.

A custom bayonet Perfect Hood is provided to protect the front of the lens from extraneous light. Nature and sports photographers will appreciate the performance and versatility of this amazing new superzoom lens from Sigma.

Expand your Ultra Telephoto World with Sigma EX APO Tele-Converters. It's easy to approach 1000mm Ultra Telephoto World with Sigma 2x EX APO TC. This 50-500mm f4-6.3 EX lens can be used with Sigma's 2x EX APO Tele-Converter as a 200-1000mm zoom lens, for manual focus. Converted f-stop display will be provided by 10 pin electronic interfaces to the camera. This Tele-Converter is fully compatible with all exposure modes as well as Program, no exposure compensation is required with the Sigma EX APO Tele-Converters.

I use this lens to shoot sports, moon, aircraft and wildlife. I love this lens and would recommend it to anyone that is looking to extend their reach. Is it heavy? Duh it is a 500mm lens after all. I use a monopod when shooting sports, aircraft and wildlife so not really an issue. I’m not sure why other users have had focus issues. I haven’t had any with mine at all. The OS is a little, just a little, loud when it is working… but nothing that would stop me from buying it again.

I have also used the 50 – 500mm sister lens to this and can say the same about it. If you’re in the market for a nice 500mm lens you will be happy with this.

This lens is an alternative to the cost of owning a Nikor lens which over 500mm rockets up 4000 easily.However this Sigma lens is frustrating to focus on wildlife that's moving and needs some techniques to learn to focus since it's rough on the camera's servo. You will end up shooting and returning to reshoot subjects twice as much than with an expensive faster lens, but there's no other choice out there for a cheaper quality lens than this.

This is a very heavy duty lense. It is only functional with a tripod. I find it is best focus the subject at 50mm and then zoom. I bought this lense for wildlife and ocean shots. It isn't a fast lens so you should be aware of that when shooting. You need to have an idea of what you want to shoot before using this lense.

A great lens for sports if you don't have $9,000 to drop on a 400mm f/4G Nikor lens. Your not going to have the lots of options for shooting at high speed in low light, but in full sun you are going to get spectacular images.

This is a great lens for nearly any use. I get great photos both up close and at far distances. I love the quality of the pictures I have gotten. I always get a lot of compliments and questions about the lens when I am using it.

This is a great lens at great price. If you don't have a lot of money for big glass... this is the way to go. You should be using a telephoto on a tripod anyway so the lack of VR is not a problem here. On a DX format digital this lens gives you the equalivalent of a 750mm lens. I've used this for sports photography and birds. The bokah is pleasing, the autofocus is fast. This lens is rugged and has survived years of being bounced around, lugged through the mountains, the rain...

Works Great with MonoPod or Tripod.Strap works good attached to lens arm with monopod . releaves stress to camera body.Also have used tripod-monopod from Ritz Camera.works well just allow time for tripod to settle,and use remote.camera was Canon 30D.